The invention relates to a refractory plate for a sliding gate valve.
A refractory plate, which is not surrounded by a metallic band, is provided in a sliding gate valve as disclosed in DE-C2 35 22 134. At least two opposing regions of an edge of the plate taper towards a sliding surface. These tapering edge regions are intended for engagement with a matching, bevelled surface of a clamping element. The dimensions and angles of the plate are so selected in the region of the bevelled surfaces from the sliding surface to a rear engagement surface that the clamping elements exert a force component directed not only towards the center of the plate but also towards the rear engagement surface. The plate can have a rectangular shape with rounded corners or a hexagonal shape which is constituted by two equal sided trapeziums with a common base.
This known way of clamping refractory plates in a sliding gate valve is associated with various disadvantages. On the one hand, a number of clamping elements provided for clamping the plate are tightened individually against corresponding edge regions of the plate by means of screws or the like. This results in a disproportionate amount of work in the installation process. Furthermore, satisfactory functioning of the screws and the threaded holes in the long term is not guaranteed in the extremely rough and hot operating environment. Furthermore, the refractory plates with the bevels provided in their edge regions are relatively expensive to manufacture, and the sharp plate edges caused by these bevels can easily break away, particularly on impact.